Musannaf Ibn Abi Shayba 13:2002

Abu Bakr narrated to us, he said: Abu Mu'awiyah narrated to us, from al-A'mash, from Shaqiq, who said: Mu'adh arrived from Yemen with slaves during the time of Abu Bakr. Umar said to him, "Take them up to Abu Bakr." He said, "And why should I take my slaves up to him?" He said, "So he departed to his house and did not take them up." He spent his night, then when he reached the next morning, he took them up to Abu Bakr. Umar said to him, "What has changed your mind?" He said, "I saw myself in what a sleeper sees, as if I were being led to a fire, and I took hold of my waist-wrapper, and it prevented me from entering it. So I thought that they were these slaves." Abu Bakr said to him, "They are yours." When he departed to his house, he stood to pray, and he saw them praying behind him. He said, "For whom are you praying?" They said, "For Allah." He said, "Go, you are for Allah."